Related Experiment Video

Updated: Aug 31, 2026

Identification of Host Pathways Targeted by Bacterial Effector Proteins using Yeast Toxicity and Suppressor Screens
07:40

Identification of Host Pathways Targeted by Bacterial Effector Proteins using Yeast Toxicity and Suppressor Screens

Published on: October 25, 2019

Inhibition of chlamydial infectious activity due to P2X7R-dependent phospholipase D activation

Robson Coutinho-Silva1, Lynn Stahl, Marie-Noëlle Raymond

  • 1Université Paris 7, Institut Jacques Monod, CNRS UMR 7592, 2 place Jussieu, 75251 Paris cedex 5, France.

Immunity
|September 23, 2003
PubMed

Insights

Adenosine triphosphate (ATP) treatment kills Chlamydia trachomatis by activating the P2X(7)R receptor. This process involves phospholipase D (PLD) activation, promoting vacuole-lysosome fusion and inhibiting bacterial infection.

Area of Science:

  • Cell Biology
  • Immunology
  • Microbiology

Background:

  • Chlamydia trachomatis evades host defenses by preventing vacuole-lysosome fusion within macrophages.
  • Understanding host-pathogen interactions is crucial for developing antimicrobial strategies.

Purpose of the Study:

  • To investigate the mechanism by which ATP treatment eliminates Chlamydia trachomatis within host cells.
  • To elucidate the role of the purinergic receptor P2X(7)R and phospholipase D (PLD) in Chlamydia infection control.

Main Methods:

  • Macrophages infected with Chlamydia trachomatis were treated with ATP.
  • The role of P2X(7)R was assessed using P2X(7)R-deficient macrophages.
  • Phospholipase D (PLD) activity was monitored, and its inhibition was tested.

Main Results:

  • ATP treatment induced Chlamydia killing via P2X(7)R ligation.
  • Chlamydial killing was dependent on phospholipase D (PLD) activation.
  • P2X(7)R ligation promoted fusion between Chlamydia vacuoles and lysosomes, preceding macrophage death.
  • PLD inhibition rescued Chlamydia in ATP-treated macrophages, but did not prevent macrophage death.

Conclusions:

  • P2X(7)R ligation triggers a cascade involving PLD activation, leading to vacuole-lysosome fusion and Chlamydia eradication.
  • This pathway represents a novel host-directed mechanism for controlling Chlamydia trachomatis infection.

More Related Videos

Markerless Gene Deletion by Floxed Cassette Allelic Exchange Mutagenesis in Chlamydia trachomatis10:35

Markerless Gene Deletion by Floxed Cassette Allelic Exchange Mutagenesis in Chlamydia trachomatis

Published on: January 30, 2020

Related Concept Videos

Bacterial Phylum Chlamydiae01:29

Bacterial Phylum Chlamydiae

The phylum Chlamydiae or Chlamydiota is composed of a single order, Chlamydiales. This phylum consists entirely of obligate intracellular parasites that infect eukaryotic hosts. While human pathogens within this group have been studied extensively, the phylum encompasses many species capable of interacting with various eukaryotic organisms. Members of Chlamydiae are typically small cocci, approximately 0.5 μm in diameter, and exhibit a distinctive developmental cycle. As is characteristic of...
GPCRs Regulate Adenylyl Cylase Activity01:09

GPCRs Regulate Adenylyl Cylase Activity

Some GPCRs transmit signals through adenylyl cyclase (AC), a transmembrane enzyme. AC helps synthesize second messenger cyclic adenosine monophosphate (cAMP). AC catalyzes cyclization reaction and converts ATP to cAMP by releasing a pyrophosphate. The pyrophosphate is further hydrolyzed to phosphate by the enzyme pyrophosphatase, which drives cAMP synthesis to completion. However, cAMP is rapidly degraded to 5′ AMP by the enzymes phosphodiesterase (PDE), preventing overstimulation of cells.
Two...
Indirect-Acting Cholinergic Agonists: Mechanism of Action01:18

Indirect-Acting Cholinergic Agonists: Mechanism of Action

Indirect-acting cholinergic agonists work by interacting with an enzyme called acetylcholinesterase (AChE) in the synaptic cleft. They can be reversible or irreversible inhibitors and have different effects on the enzyme.
Reversible inhibitors like edrophonium bind to a specific part of the enzyme called the anionic catalytic site. They form noncovalent bonds, which means they are not strongly attached to the enzyme. This creates a temporary and less stable enzyme–inhibitor complex, leading to...
Inhibitors of Gram-positive Cell Wall Synthesis01:23

Inhibitors of Gram-positive Cell Wall Synthesis

Bacterial cell walls are typically rigid structures composed mainly of peptidoglycan, a mesh-like polymer that provides mechanical strength and maintains cell shape. The synthesis of peptidoglycan is a crucial process in bacterial growth and serves as a primary target for many antibiotics.Mechanism of Action of Beta-Lactam AntibioticsBeta-lactam antibiotics, such as penicillin, inhibit peptidoglycan synthesis in actively growing cells. These antibiotics share a characteristic four-membered...
GPCR Desensitization01:12

GPCR Desensitization

G protein-coupled receptor (GPCR) signaling plays a crucial role in cell functioning. GPCR desensitization is an equally essential process. It allows cells to respond to changing environments and regain sensitivity to new stimuli while preventing unnecessary stimulation when no longer needed. Prolonged exposure to stimuli leads to GPCR desensitization. It involves blocking the receptors from binding and activating additional G proteins. This inhibits activation of downstream effectors, thereby...
Gene Regulation in Microbial Communities: Quorum Sensing01:28

Gene Regulation in Microbial Communities: Quorum Sensing

Quorum sensing is a mechanism of bacterial communication that enables coordinated gene expression in response to changes in population density. This facilitates collective behaviors that enhance survival, resource acquisition, and ecological adaptation. This process relies on small signaling molecules called autoinducers that accumulate as bacterial populations grow. When a critical threshold concentration of autoinducers is reached, bacterial cells collectively modify gene expression,...